Alizarin preparation and process of making.



EMXLFRANKE, F GRll TNAU, NEAR BERLIN, GERMANY, ASSIGNOB TO GHElVll-SCHE FABRIK GRll'NAU' LANDSHOFF AND MEYER AKTIENGESELLSCHAFT, OF GRUNAU,

GERMANY.

ltlo Drawing.

To an whom it may concern:

ist, a subject of the German Emperor, lfilti ing at Griinau, near Berlin, Germany, have invented certain new and useful ln'lprovcmcnts Relating to Alizarin Preparations Suitable for Dyeing and Printing, of which the following is a s )eci.ti mtion.

Experimeuts made for converting alizarin- 0 sodium into alizarin and sodium fol-unite by treatment with carbimic acid, liave shown, that this operation cannot be carried through successfully. The final product is a liquid, which. has a Very weak alkaline reaction, absorbs carbonic acid very slowly and contains in addition to sodium t'orn'iate, alizarinsodium and alizarin in solutiml. This solution may be boiled down to dryness, with out causing the separation of tree alizarin. By the addition of yvater the dry substance may be redissolved. l

Experiments have shown, that mordanted cotton may be dyed with the solution. The

product obtained described is a new alir;

arin preparation rich in alizarin soluble in water and capable of dyeing cotton in the same manner as commercial alizariu in the shape of paste. Further experiments have shown, that alizarin may be caused to enter, 7

into solution also by caustic soda solution. corresponding in quantity to the monosodium salt, and that with this solution cotton may be dyed as with. the alizarin paste. These dyes had a more bluish tint'than that obtainable with the same kind. of aliaarin without the addition otsoda lye. Fuller tints may however be obtained, as shown by (BXpClilIlQIttS, by adding sodiiun formate equivalent in quantity to the sodium lye. The sodium fol-mate may be rcplaccal by the SOCllUllbEtCQttttt. or by the sodium salts of tartaric acid, lactic acid or similar or anic acids, or by the sodium salts of weak lnorganic acids, such as boracic acid. A

monosodium salt of alizarin soluble in water may therefore be obtained by the addition of the quantity of sodium or potassium lye corresponding to this salt of alizarin and by boiling down to dryness in the presence or Without the presence of alkali salts of organic acids or weak inorganic acids, may. be converted into a concentrated dry alizarin preparation.

As regards solubility and coloring power the alizarin preparations to which salts of ALIZARIN PREPARATION AND PROCESS Q13 MAKING.

Specification of Letters Patent. Patentggdl July 26, 191%. Application filed July 9, 1909. Serial No. 566,776. 3 I

sodiumorfpotassimn have been added'are superior to the pure inonosodium or monopotassii1m-a1izarins The manufacture may be modified by first producing the disodiurn-sa'lt of alizarin and' 0 then formii'lg the mtmosodium salt by addition of acid. Preparations obtained in this manner are distinguished by their easy solnbility. The above described treatment of alizarin maybe applied also to purpurin and isopu rpurin. w

lhc connnercial advai-ltages of the dry preparations in comparison with the pastes usually formed incon'imercev are firstly the greatconccntration (more than'70 per cent. ofalizarin) facilitatingtransportation, and secondly the easy solubility, which insures a much better distribution "ofalizariu in the bath, than ispossible with the best paste. Further advantages are the facility of weighing oft" "predetermined quantities ofthe dry-powder, the avoidance of the liability to 'dry up," which is vvery troubleson'ie in the case of pastes, and after which an equally fine'distribution cannot be obtained, and the strength of the paste is not accu-' rately known. Further advantages appear in the utilization of these preparations in the process of printing inasmuch as the impressionspenetrate better, and are therefore more permanent, and the v rinting rollers are not liableto be smudgedl In localities, where the cost of transportation of aliza-rin in the shape of paste is not important in comparison with the cost of producti(m' of the dry alizarin, it may be possible with an alizarin solution produced in the manner .described, to work "more cheaply than with the dry a'lizarin preparation, and that the color eitcct will be equally advantagcmis. In comparison with the ali aarin in the shape of paste the dyer has the great commercial advanta 'e of being able to dyewith the alizarin so ution in the apparatus.

What I claim is r t 1. The process for obtaining alizarin preparations suitable for ,dyein'gand printing, which consists in dissolving alizarin by means of an alkali solution not exceeding in quantity that corresponding to the 1nonoalkali-salt 0t alizarin, substantially as described.

2. The processfor obtaining alizarin prep arations suitable for dyeing and printing,

- of an alkali-solution in which consists in dissolving alizarin by means of an alkali-solution not exceeding in quantity that corresponding I the monoalkali-salt of ali'zarin of organic acids substantially as described.

3 The process for obtaining'dry soluble and concentrated alizarin preparatlons suitable for dyeing and printing vlrhich consists in forming a solution of ahzarin by means of alkali-solution in ;uantity not exceeding that correspondin to the mono-alkali-salt of alizarin, and boiling down the solution to dryness, substantially as described. 1

4. The process for obtaining dry soluble and concentrated alizarin preparations suitable for dyeing and printing, which consists in forming a solution of ahzarin by means quantit not exceeding that corresponding to th '1 mono-alkalisalt of alizarin, adding alkali salts of organic acids and evaporating to dryness, substantially as described.

- 5. An al-izarin preparation formed by disand addin'g'alkali salts solving alizarin in a quantityv of alkali-lyecorres onding in quantity to t e mono-alkali salto alizarin, the said preparation unlike the normal sodium salt of alizarin bein capable of dyeing mordanted cotton, an being less soluble in water than the disodium salt, substantially as described.

6. A dry and concentrated alizarin pre aration soluble in water and consisting o? a mixture of alizurin and a mono-alkali-salt of alizarin and a salt of an organic acid, the said mono-alkali salt of alizarin, unlike the normal di-alkali-salt of alizarin', bein capable of dyeing mordanted cotton and ing less soluble in water than the disodium salt, substantially as described. p

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

EMIL FRANKE.

'- Witnesses:

PAUL Jncro, WALTER SAECHSLING. 

